Twenty three years after her sister’s death, Jennifer LeCornu Carrieri paid for three billboards and posted a $100,000 reward for information leading to the arrest and conviction of her killer. (Jennifer LeCornu Carrieri) (Jenny LeCornu Carrieri)

Someone knows why Jody LeCornu was sitting in her white Honda Civic, making phone calls from an empty shopping center parking lot in Towson, Md., at 3:40 a.m. on a cold Saturday in early March 1996. Someone knows who drove up to LeCornu’s car, spoke to her and then fired one shot from behind her, the bullet smashing the left rear passenger window, slicing through the driver’s seat and then into her back. And someone knows the identity of the stocky man who approached her car again -- after she drove across the street to another shopping center on York Road -- as it idled against a curb, reached in and pulled something out, then drove away in a white BMW.

LeCornu’s twin sister, Jennifer LeCornu Carrieri, hasn’t given up on finding that crucial witness. And on the anniversary of her sister’s death, Carrieri paid for three large billboards in the heart of Baltimore, and has posted a $100,000 reward for information leading to the arrest and conviction of LeCornu’s killer. “FIND MY KILLER” the billboards implore, above a photo of a smiling LeCornu.

The crime happened in Baltimore County, just north of the city limits, and Carrieri originally commissioned a billboard on York Road not far from the scene. But in recent weeks, she placed the billboards on Pulaski Avenue, Greenmount Avenue and South Hanover Street in the heart of Baltimore City, in hope of reaching someone who knows who fired the fatal shot into her 23-year-old sister.

Jody LeCornu was shot to death at age 23 in Towson, Md. Police are still seeking her killer. (Baltimore County Police Department)

For years after the shooting occurred on March 2, 1996, the women’s father, John LeCornu, an assistant prosecutor in Anne Arundel County, handled the family’s contact with Baltimore County Police. But he became ill and died in 2007, Carrieri said. “All of a sudden, one day,” she said, “I had a backbone.”

So Carrieri became the one who kept in touch with investigators on the case, including Carroll Bollinger, the lead homicide detective the entire time. Carrieri contacted people at news outlets, websites, crime shows, magazines, podcasts — anyone who would spread word of the case just a bit further. Carrieri got the idea for the billboards from the Academy Award-winning film “Three Billboards Outside Ebbing, Missouri,” about a mother seeking justice for her daughter, who was killed.

Carrieri wanted to hire a private investigator to look at the police case files to determine whether anything else might be done. But because the case is still open, Baltimore County refused to release them. Carrieri filed a lawsuit seeking access to the case but ultimately reached a confidential settlement that did not result in the files being released. Maryland statute allows law enforcement agencies to withhold investigative files indefinitely, although they also have the discretion to release files.

Joann “Jody” LeCornu grew up in Annapolis, graduated from St. Mary’s High School, and in 1996 was a student at Towson State University. She also worked part-time at a bank in Hunt Valley, Md. Police know that LeCornu spent the evening of March 1 drinking at the Mount Washington Tavern in Baltimore, about 3.5 miles from York Road in the Towson area. A regular at the bar, LeCornu stayed until closing time, then drove a bar employee home and stopped at a liquor store for beer, police have said.

Jody LeCornu was found fatally shot in her Honda Civic on the morning of March 2, 1996, in Towson. (Baltimore County Police Department)

By about 3:30 a.m., LeCornu was parked in what was then called the Drumcastle Shopping Center, in the 6400 block of York Rd., police said. Phone records show that she made several calls around that time, including to the Mount Washington Tavern and to a friend. A light snow was falling.

Despite the late hour, at least one witness saw a white BMW pull up near LeCornu’s Civic, police said. The other driver was described as a stocky black male wearing a green Army-style coat. “There was some type of interaction between the suspect and Ms. LeCornu,” said Baltimore County Cpl. Shawn Vinson, the head police spokesman. “Then a shot was heard.”

It was about 3:40 a.m. After being once in the back, LeCornu pulled out of the Drumcastle lot (now a government center), drove across York Road into the York Road Plaza, and circled the parking lot there before stopping in front of a Giant grocery store. Carrieri said multiple witnesses saw the BMW pull up alongside LeCornu’s car, the stocky man get out of the BMW and walk over to the Civic, where he reached inside and pulled something out. LeCornu’s purse was not found, Carrieri said.

A white BMW similar to one believed to be involved in the March 1996 slaying of Jody LeCornu. (Baltimore County Police Department)

Carrieri was living in California at the time but in constant contact with her twin, running up huge phone bills. “When she died, everything just went black,” Carrieri said. “Numb. I was just so numb for a long time.”

Carrieri soon returned to Annapolis, got married and started a family. But her sister’s death gnawed at her, and her interactions with Baltimore County police left her frustrated. She paid a lawyer $20,000 to sue the police for their files. She started a website. She helped increase the reward fund from $32,000 to $100,000. She paid for a billboard on York Road just south of Towson, and now the three billboards in central Baltimore. She spoke to anyone, even prison inmates, who might have a lead.

Her personal life suffered, Carrieri said, but “I didn’t care. I’m going to find her killer. I’ve become very obsessed with her case.”

Vinson said that police have never had enough information to identify the shooter, and that “we welcome any help from the public. We’re wondering if people are talking about it. As time goes on, people tend to relax and may talk about it a little more. We’re hoping a relative or maybe a person in jail may have heard something.”

Anyone with information about the LeCornu’s killing can call Baltimore County Police at 410-887-3943, Maryland’s Metro Crime Stoppers at 866-756-2587 [866-7LOCKUP], or submit information through the website www.metrocrimestoppers.org.

Jennifer LeCornu Carrieri, the twin sister of Jody LeCornu, visits her grave at Lakemont Memorial Gardens in Davidsonville, Md. Carrieri has been pushing for answers in her sister's 1996 killing. (Kira Carrieri)